Polymeric pipes have replaced metal pipes in many applications such as high-pressure fluid transportation. Polymeric pipes have several advantages over metal pipes including being of relatively lighter weight, more corrosion resistant, inexpensive, more thermally and electrically insulative, tougher, more durable and more easily shaped during manufacture. Such pipes are exposed to numerous stresses during their lifetime that may result in cracks or breaks that are expensive to repair, especially in situations where the pipe is buried in a structure or underground. As such polymeric pipes may be required to meet industry-defined standards depending on their intended use. Polymeric material used in the fabrication of pipe has often been optimized to provide a more durable end-use article.
Polyethylene compounds are known for the production of pipes for the transport of fluids under pressure. Such pipes may require high stiffness, combined with a high resistance against slow crack growth as well as resistance to crack propagation yielding impact toughness. Polyethylene pipes are widely used as they are lightweight and can be easily assembled by fusion welding. The polyethylene pipes made of these polyethylene compounds usually have a good resistance to stress cracking. However, when these pipes are embedded in or posed on a soil comprising rocks and stones, scratching of the pipes can occur giving rise to crack growth. Moreover, point loads on the pipeline can occur by rock impingement and also give rise to crack growth.
Thus there is a need for improved polymeric compositions and methods of fabricating polymeric pipe.